The invention relates generally to protective coatings. More specifically, the invention relates to protective coatings that are used in optoelectronic devices.
Optical and optoelectronic devices that are susceptible to reactive chemical species normally encountered in the environment, require protective coatings with good barrier properties. Quite often substrates, especially polymeric substrates on which these devices may be a manufactured, are not atomically smooth and have surface spikes that are hundreds of nanometers high. Also, the exposed surfaces of these devices may be scratched and damaged during fabrication and/or transportation. These surface defects may often limit the performance of these devices. Defects could lead to a short in the device by forming a contact between anode and cathode and pinholes in various functional coatings could help the permeation of moisture, oxygen and possibly other deleterious materials.
It would therefore be desirable to have coatings that are substantially smooth and defect free, having low permeation rates for chemically reactive species such as oxygen and water vapor and are chemically resistant to commonly used chemicals for device fabrication to protect an unencapsulated device or protect other functional layers or coatings in a device.